1. Field of the Invention
The present invention relates to an image forming apparatus in which a cartridge is detachably attached to an apparatus main body and in which an image is formed on a recording medium.
2. Description of the Related Art
As an image forming apparatus, there exists an electrophotographic image forming apparatus. Here, the electrophotographic image forming apparatus forms an image on a recording medium by employing an electrophotographic image forming process. Examples of the electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (e.g., a laser beam printer and a light-emitting diode (LED) printer), a facsimile apparatus, and a word processor. The recording medium is a medium on which an image is formed by an electrophotographic image forming apparatus; examples of the recording medium include paper and an overhead transparency (OHT) sheet.
Regarding the above-mentioned electrophotographic image forming apparatus, there has been discussed a construction in which a scanner unit serving as an exposure unit is mounted on a cover member that opens and closes an opening for attaching and detaching a plurality of cartridges. According to the discussed construction, the scanner unit is retracted when the cover member is opened for attachment/detachment of the cartridges, thereby achieving an improvement in terms of operability in the attachment/detachment of the cartridges (see U.S. Pat. No. 7,356,283). Further, in this connection, as a result of the recent reduction in the size of image forming apparatuses, there has been generated a requirement to suppress the height or the size in the width direction of the image forming apparatus. Thus, in an image forming apparatus of the type which uses a plurality of cartridges, the distance between the cartridges is becoming smaller and smaller.
U.S. Pat. No. 7,356,283 discusses an image forming apparatus capable of color image formation. In this image forming apparatus, a plurality of cartridges are adjacent to each other obliquely up and down. In the image forming apparatus discussed in U.S. Pat. No. 7,356,283, the scanner unit is mounted on the cover member, so that the scanner unit is retracted when the cover member is opened, thus facilitating the attachment/detachment of the cartridges.
However, since the scanner unit is mounted on the cover member, the cover member is so much the thicker; in the image forming apparatus as discussed in U.S. Pat. No. 7,356,283, if an attempt is to be made to reduce the height of the apparatus main body, a part of the opening for the attachment/detachment of the cartridges has to be stopped.
Thus, when attaching/detaching a cartridge to the attachment position nearest to the scanner unit, with the cover member being open, the scanner unit may hinder smooth attachment/detachment of the cartridge.
Thus, the scanner unit mounted on the cover member may constitute an obstacle to a reduction in the size of the apparatus main body.
Even if the scanner unit is not mounted on the cover member, there might be cases where the attachment/detachment of the cartridge to/from the attachment position nearest to the cover member is rather difficult to perform with the cover member being open.